I have recently added the Stillen supercharger, innercooler, carbon fiber hood, nismo cat back exhaust, had the seats redone in carbon fiber, stripe kit. This was about a month ago.
Now its in the shop again getting 20" rims, new stillen air intake system, new spoiler, smaller pulley on blower thats supposed to give 1 more lb. of boost.
Next visit it gets the shift kit installed (its auto)
Im getting carried away, but it sure is fun!!!!!!!
It is downright MEAN!!!!!!!!!!

 

all that power, and 20" rims? thats not gonna feel too good.

 

I'd like to see some pics of your beast.

 

how come????

 

how come???? should I go smaller????

 

Let's see some pics!!! Sounds like a sweet ride

 

Larger wheels will hurt performance.

 

the flag is rising

 

lol, don't raise it just yet

 

well it hurts performance for one thing, but ride quality with so little sidewall; your gonna find traction comes and goes instantly, there will be no warning, youll just start sliding.

the sidewall is generally the shock absorber for all movement parralel to the ground. foward, back, side to side. every little tap of the gas or turn of the wheel the wheel absorbs and smooths out the transistion. less wheel, more jolts, more loss of traction.

youll notice even nascar and indy run the smallest rim that will clear their brakes.

 

There is nothing wrong with a 20" wheel. What is more important is the tires. The Carrerra GT, 911's,M3's,M5's all run fine with 20" wheels (either straight or staggered). Some of these come from the factory with 20" like the GT. You will not know any performance changes except for more road feedback unless you track your car. They look very close in size to 19" (most people cannot visually tell the diff) but better tires are avail in 20". I do not know why everybody always give the wrong info about 20" wheels. You can get 20" wheels lighter than the factory 18. You can get 17" wheels heavier than 20" it is up to you. Just get good tires. 5 years ago I was running 19" on a GS400 and every was saying the same thing about 19" that they are now saying about 20". Stick with P Zeros, Pilots or Continentals and you will be ok.

 

20" does hurt performance, a lot

 

rotational inertia is a bad thing. Yeah you probably could get lighter 20 inch wheels but the majority of that weight is further from the axis or rotation, which takes more energy to turn.

 

i have never seen a set of 20" wheel lighter than the factory 18s which weigh in at 25lbs? id bet even the 20" forged volk gt-cs weigh the same if not more.

 

In what area does a 20" wheel hurt performance. Cornering, traction, speeding - these factors are influenced more by the tire than wheel. Look on tirerack.com and see how much using different tires changes overall lapping time. Has anybody (who believe in the hurt performance claim) actually driven a +1,+2,+3 wheel change on the Z or any car. Ten/twenty years ago Porsches, Lambos, and other sport cars came with 15",16",17" wheels on there top models. Why do you think the diameters became larger over time. To hurt performance? Or is it that the tire makers now make larger tires to fit and even the auto designers can see performance gains in using these larger wheels.

 

actually i think that the rim sizes increased due to style more than performance. every race team will pick the largest side wall with a small rim. look at drag, nascar, jgtc.

 

check this link:

http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html

click on Mechanics, Rotation, then Moment of Inertia

 

someone seriously needs to educate alddave on this stuff... i can see powertrip and hraesvelg have tried but it's not working...

bigger diameter wheel = higher moment of inertia, less sidewall on tire (finite clearance under the fenders)

moment of inertia is always a multiple of MR^2 (depending on specific shape) which means at the same weight and shape/design, a 20" wheel will take 23.5% MORE TORQUE to turn than a 18" wheel and 38.4% more torque than a 17" wheel (the constant and the mass cancel out when you divide to find the ratio). that means that THAT MUCH LESS POWER is delivered to the asphalt, where it helps move the car.

also, the sidewall of the tire has a LOT to do with performance. as you go into a corner hard, the sidewall flexes and puts more of the outside shoulder onto the pavement, which improves grip. if you look at any tire, the contact patch is never perfectly flat. it's got a slight curve on the outer edges. and it's the sidewall flex that puts that rubber on the road to give you added traction in extreme conditions. all things being equal (same tire, same wheel width, same mass, same overall wheel/tire diameter) except for the wheel diameter, the smaller wheel/tire combo will give you better performance.

the truth is, people who increase wheel diameter will almost always increase wheel/tire width, which might yeild better performance, but alddave, you never mentioned wheel wheel width... just wheel diameter.

again, this has all been said before, but some people just aren't getting it...

 

i HAVE DONE THE SAME MODS TO MY 350 Z . I HAVE THE STILLEN EXHAUST. I PUT ON RANDOM CATS AND STILLEN HEADERS.
266 HP. REMOVED THE CATS AND GOT 273. IF I REMOVE THE HEADERS I SHOULD GET 285 OR A LITTLE MORE. HAVE YOU DYNOED YOUR CAR IF YOU HAVE I WOULD LIKE TO KNOW WHAT
RWHP YOU HAVE.
NEXT MOD COMING IS VALVE BODY AND TORQUE CONVERTER.
AND A ECU FLASH .

 

WOW, THAT SOUNDS LIKE A COOL SETUP YOU HAVE THERE, BUT IF YOU REMOVVE THE HEADERS WON'T THAT BE REALLY LOUD? SO LOUD THAT YOU COULDN'T YELL OVER THE NOISE? I DON'T LIKE TO YELL.